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Art. XII. — Observations on Living Polyzoa. 

 By C. M. Maplestone. 



[Read August 11th, 1881.] 



Many of our Polyzoa have lately been described in Professor 

 M'Coy's Decades of our Fauna, and some new species to 

 this and to the Microscopical Society ; but as very little has 

 been said concerning the animals themselves, or the appear- 

 ance of the Polyzoa in the living state, I think the presen- 

 tation of my observations of such species as I have found 

 living at Portland will be opportune.* 



The number of the tentacles varies from 8 to 24 ; 

 generally they are in multiples of 4. I had supposed 

 always so; but Seruparia chelata has 10 tentacles; JEtea 

 anguina has generally 12, but in some cells on the 

 same piece I observed the polyps had 13 tentacles; Dip- 

 lopora cincta has 13, and Catenicella formora 18. The 

 number of tentacles possessed by the different species of the 

 same genus varies, so that, apparently, these details of the 

 structure of the polyp will not assist towards the classifica- 

 tion of them, which will depend, as hitherto, upon the form 

 and structure of the cell or ectokyst. It will be noticed, 

 however, that the Cheilostomata have never less than 10 

 tentacles, and that those belonging to the Cyclostomata and 

 Ctenostomata have only 8. I hope to be able to make 

 further observations of the animals of the three divisions, as 

 I have found inany more species than those mentioned in 

 such a condition that I do not despair of greatly extending 

 the knowledge of them, and I hope to be able to elucidate 

 their life history in the course of time. 



These observations have been made within the last two 

 or three years upon specimens either dredged, obtained from 

 old piles, drawn up from the pier, or washed up on the 

 beach. While some of those dredged, or carefully collected 

 from the piles, and immediately transferred into bottles of 



* The only published observations on the living animals of Australian 

 species are contained in a Paper by Mr. J. R. Y. Goldstein, in the "Journal of 

 the Microscopical Society of Victoria" for May, 1880. 



